Make 'em blush
by Rex888
Summary: They wanted to see him blush. That was it. Sans was blue, everything about him had a touch of blue and despite never having seen him blush Frisk knew it would be blue. It's gonna get naughty up in here.
1. Chapter 1

They wanted to see him blush. That was it. They knew that when Papyrus blushed it didn't look all that different, the orange quite a natural shade that matched his colour scheme but Sans. Sans was blue, everything about him had a touch of blue and despite never having seen him blush Frisk knew it would be blue.

It was with this thought that 15 year old Frisk fell asleep halfway through getting into their pajamas.

When morning reared it's ugly face and Frisk still hadn't risen Toriel decided enough was enough and it would be nice if Frisk could join the others in the land of the living and awake.

"Sans, would you be a dear and wake Frisk up, they've slept long enough, if they don't wake up soon they won't sleep tonight" Toriel rubbed a fur covered paw over her muzzle, "if that happens they'll be groggy for school."

"and we all know a "bone-tired" frisk is a grumpy frisk" Sans stood up from the table with a sigh, sadly abandoning the freshly made coffee that he was going to regret not drinking later when Undyne was going to inevitably find him napping on the job.

When Frisk had freed them all 5 years prior the monsters had been well accepted, no one that remembered the old tales were alive to fear them and as such they had been welcomed with welcome arms despite the political nightmares that were accepting magic and monsters were real, they did not actually kidnap a child and now they needed to find a place for the monsters to live.

Sans, Papyrus, Toriel, Alphys, Undyne and Frisk had all moved in together with Asgore popping in from time to time. Toriel's room was in the centre of the house to allow easy access to every room if needed. Sans, Papyrus and Frisk had rooms that were all next to each other with Sans in the middle. Finally, Alphys and Undyne had chosen to share the attic. Sans was certain they were up to adult shenanigans most nights.

He wasn't up to asking them how it worked if that's what they were actually doing.

Trudging up the stairs Sans contemplated how he was going to wake the kid up, he ignored the voice in the back of his head saying that Frisk had probably been dealing with night-terrors again, he'd just chosen to ignore it.

He knocked first, in case they'd just chosen not to get up and were just lying in bed. When he didn't get a response he called out, slightly pushing the door open. When that still didn't elicit a response he walked fully into the room, a pun on the tip of his tongue.

"hey kid, why did the skeletons stay in be-"His sentence shuddered to a stop when his brain caught up to what he was seeing.

The sheets were a tangled mess, a single, visible leg sticking out from one end of the bed. Sans couldn't take his eyes away, he knew he should but as his eyes traveled further up and blue blossomed on his face he couldn't tear his eyes away.

She, for Sans was certain Frisk was female, was lying on her front with her left arm hugging the pillow, her right flopped out behind her so that her hand hid under the linen. The sheets had fallen, or rather, had been kicked half off the bed so that they exposed everything above the hips. An elegant, womanly form that had once been hidden by an oversized, striped jumper was now on show, just for Sans.

By this point his face and neck had turned a bright cyan, a darker sapphire shade brushed across his cheeks and over his nose, his pupils has become bright white dinner plates, so large there was almost no sclera. His irises shone bright, fueled by his embarrassment and something else he couldn't quite place.

He was stuck fast to the plush floor, unable to rip his eyes from the view of Frisk's breast, the nipple just hidden as she was squished into the mattress. Finally getting his brain into gear he yelled, startled, his blush glowing to the point where he had illuminated the room with a kind and calming blue, a stark contrast to the inner turmoil he was feeling.

He dashed from the room, his arm covering his face with a strings of "omg", "im so sorry" and "i didn't mean to see that".

If he had looked back he would have seen Frisk's groggy, drool covered face lift up out of the mattress only to fall back into the pillow with a snore.

He practically jumped the bannisters into the front room, sprinted in through the kitchen and straight into the family dining room.

"IDIDNTMEANTOWALKINLIKETHAT! SOMEONEELSEISGOINGTOHAVETOWAKEHER-IMEANTHEM-UP" With boths hands covering his face he took a gasp of air and muttered out a final "preferably someone female needs to go wake frisk up" before collapsing onto the nearest sofa, accompanied by a muffled "eeeeeeeeeeeeeeeeee"

"Uh, Sans, you alright there guy?" Undyne's face was a picture of confusion and concern. It's not everyday everyone's favourite chilled skeleton comes screaming into a room glowing like a blue lightbulb.

"mmmmmmmmmmmmnnnnnnnnngggggghhh" Was the response that was given as Sans's blush slowly decreased to the point he was no longer the brightest source of light in the room. Getting himself together Sans sat up and wiped a hand down his face so he was gripping the collar of his shirt. He wouldn't look at anyone and his right hand was down by his said, clasping the edge of the beige sofa's cushion. His very being screamed embarrassment.

"Sans, are you quite alright, I don't think I've ever seen you so flustered?" Toriel stared down with a motherly gaze.

"YES BROTHER? WHAT HAS OCCURED TO TURN YOU INTO A LIGHTBULB?" Papyrus had come into the dining room, a bowl of cheese and ham pasta lightly steamed as he placed it onto the communal table.

"ALSO, WHY HAVE YOU NOT RETURNED WITH FRISK?"

"Yes, I'd like to know that too, did I not send you up specifically with the intent to rouse young Frisk?" She had a small, sad, disappointed frown, one you would expect from a mother getting an explanation from a child that had lied about homework.

Sans had calmed down considerably but there was still a light blue tinge to his cheeks and he still wouldn't look at anyone. Every few seconds the blush would deepen again.

"i-uh...you see…." His eyes started darting, he looked like a kid who'd been caught in the cookie jar. He looked up at the ceiling and sighed. "aaaaah, someone female go and wake them up"

The first to come to their senses was Undyne, shaking her head and grinning she patted the top of Alphys' head from her place behind the settee opposite Sans. "I'll get the little runt out of bed, I'll drag 'em out here naked if I have to! Fuhuhuu!"

"dont do that!" Sans was back to being a light bulb.

"I wouldn't actually…..pervert…." She glared at him.

5 minutes went by and everyone returned to what they were doing, Sans had left for patrol still a little blue in the face. Toriel went to feed the snails under the window, Papyrus went back to his cooking and Alphys was waiting on the sofa still wondering what was taking so long.

Another 5 minutes and a red faced Undyne came downstairs, ever so slightly sweating. She was looking at the floor glancing about the place. From behind her a rather disheveled Frisk appeared, their shirt was on backwards, their hair unbrushed and their face still wet from cleaning up the drool.

"She wasn't wearing any clothes….." With that Undyne left.

Looking abashed Frisk returned to the kitchen for breakfast and Alphys to her lab.


	2. Where r34 made it glow blue

Alrighty then, shall we try that again? I tried uploading this on my iphone...turns out that was a bad move. I love you guys, I really do, this is the first time a fanfiction of mine has become popular.

Warnings for this include glowing dicks and boobies. (The boobies do not glow)

Chapter 2

He was huffing and puffing, his face alight with blue, a dark sea blue. His face however was not the brightest source of light, that honour went to an area below the neck and again further down, below the belt. His heart beat rapidly, his soul on show to the world if they were there to watch. Luckily for their *private* partner, this was not the case.

Up, down and slide. Up, down and grind. Their breathing increased and both Sans and Frisk became more confident. In a burst of intensity Sans flipped them around as he took the dominant position, he was sure she would have squeaked if she could. If he could wish one thing of Frisk it would be that she wasn't mute, just to hear what would have been exquisite moans and squeals.

"thats it kiddo, ngh" he swallowed and increased his already frantic pace "gonna *huff* cum" he moved his hands from their position of clutching her arms above her head to moving to her thick, soft thighs. He leant over so his face was next to hers.

With a final thrust he found himself seeing white and feeling cold.

The cold temperature was not expected and neither was the bright light. The November breeze rolled over him and with a jolt he realised that he was not in a dark room with Frisk but was in fact sitting at his hot dog stand with his not-so-little friend pushing up against the now moist insides of his shorts.

"well fuck me am i right?" Oh wait, her thought, she was. Confused he spun around trying to gather his bearings and realised his shorts were still glowing from his residue. He grabbed a napkin from under the stall to wipe frantically, he knew he was going to have to get changed but he could at least make himself presentable enough to make it home. He was still too shaken from the fact he'd imagined him...and Frisk…..

He stopped right there, he could feel himself growing again. He jumped, trying to cover the light it was creating without alerting any of the passing monsters or people.

His face must have been a picture as several passers stopped and stared, a couple of people sniggering.

Holding his head from where he smacked it on the roof of his cart he checked himself over once more to ensure he wasn't glowing and gave up on his futile attempts at trying to sell hot dogs (and cats) and made to get back to their shared house.

Upon entry to the house he noticed only the upstairs light was on. _Well that's strange, looks like Frisk is still in….oh yeah, it's teacher training day._ Without paying attention to where he was going he made his way up the stairs, not noticing he was headed straight to Frisk's room. _Wonder where Tori went…_

Finally at the top of the stairs Sans started, he didn't remember coming up here. He shook his head and went to go back downstairs when he heard strained panting. He jolted, automatically thinking someone (Frisk) was in pain.

He slammed the door open and almost fell over in horror realising what he'd just walked into.

Frisk was on her back, sheets on the floor and trousers abandoned with them. Her pants around her ankles, hair in a halo behind her and hands spreading apart her labia. Upon noticing the intruder she jumped, scrunching in on herself. Her face was steadily growing redder by the second but she stopped. Eyes wide she stared.

Sans had stopped half way, hunched over slightly, still staring. The lights in his eyes had gone out but his face was flushed with blue once more. He strangled out a brief and tangled "SORRY" as he slipped out, slamming the door and slinking off to his room.

Frisk jumped again when she heard both doors slam.

 _I was right...he is blue!_


End file.
